<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        div#box{
            text-align: center;
        }
        div#box div#btn{
            margin: auto;
            width: 50px;
            height: 50px;
            line-height: 50px;
            background-color:  #ddd;
            border-radius: 100%;
            color: #fff;

        }
        #btn{
            cursor: pointer;
        }
    </style>
</head>
<body>
    <div id="box">
        <div id="btn">开</div>
        <img id="img" src="./pic_bulboff.gif" alt="" />
    </div>
    <script>
        (function(){
            var btn = document.querySelector("#btn")
            var img = document.querySelector("#img")
            btn.onclick =function(){
                if(this.innerHTML =='开'){
                    img.src = "./pic_bulbon.gif";
                this.innerHTML = "关";
                this.style.backgroundColor ="green";
                }else {
                img.src = "./pic_bulboff.gif";
                this.innerHTML = "开";
                this.style.backroundColor = "#ddd" ;
            }               
            } 
        }());
    </Script>
</body>
</html>